Structural requirements for photo-induced RNA-protein cross-linking

Cross-linking of isotope-labelled RNA coupled with mass spectrometry (CLIR-MS) was used to study the UV cross-linking behavior of in vitro reconstituted FOX1 RRM in complex with its cognate RNA sequence, the Fox binding element (FBE), (U)GCAUGU. The FBE heptanucleotide was subsequently mutated, and the impact on UV cross-linking and affinity investigated. Cross-linking was performed using irradiation under 254 nm light, relying on the inherent reactivity of ribonucleotides.